:No. 45.— 1894.] TESTUDO IN the museum. 



131 



plastron not having radiating lines, which is the case in our 

 No. 4. In fact No. 4 would be platynota if it were not for 

 ;the tubercles on the hinder sides of the thighs. If the young 

 of T. elegans and T. platynota agree, they could scarcely be 

 •considered as good species. 



In contemplating these variations, the question of natural 

 selection inevitably arises. The difference in coloration we 

 cannot imagine to be of any advantage to the different 

 individuals, crawling about as they do on the open plains 

 in the mid-day sun, and having no need for concealment. 

 Nor can we imagine that the greater or lesser development 

 -of the humps is any more advantageous ; in fact there seems 

 to be no point for natural selection to select from, and we 

 are confronted with an inherent tendency to variation, which 

 appears to me to form part of the diagnosis of many species 

 throughout the animal kingdom. That this is the case here is 

 clearly proved by the young. In this little tortoise we find 

 six vertebral scutes, but in this case the number is not 

 increased by a posterior outgrowth of the fourth, but by the 

 division of the second into two nearly equal shields. On the 

 right hand side there are four costal shields, but on the 

 left the second is broken into two large, distinct, well-formed 

 plates, making five costals on that side. I need scarcely 

 point out how interesting a series of individuals of this 

 species would be, illustrating the way in which the adult 

 characters are acquired, and showing whether the abnormal 

 characters of the young are retained or obliterated. 



I cannot feel absolute certainty about the third species in 

 our collection, as it has never been figured but once, and 

 that work is not in our library, but the magnificent diag- 

 nosis of Dr. Boulenger rarely leaves much doubt as to what 

 species an individual should be referred, and I have there- 

 fore entered this specimen on the list as Testudo ibera. 

 There are two objections to this being a Ceylon species : first, 

 that this is the only specimen ever procured ; and secondly, 

 *that the nearest locality from .which it is recorded is the 



12—94 C 



